linear systems theory

Question 1

spatial frequency

Answer 1

can be expressed in line pairs/mm

higher spatial freq, quicker the variation of spacing

Question 2

modulation

Answer 2

0-1
1 being when clearly black/white

Question 3

resolution limits

Answer 3

by pixel size, cannot have resolution better than pixel size

relative positioning, offset

Question 4

fourier transform

Answer 4

A Fourier Transform is a method of detecting what frequencies are present in a sampled
waveform. Given a set of sample data and a frequency the transform will give you the
amplitude and phase of that frequency within the sample data.
For example, say you want to know if 1Khz is present in your sample data. The fourier
transform will tell you the amplitude and phase of any 1Khz component in your sample
data

Question 5

expressing a function as a sum of sinusoids

Answer 5

H(u) expresses the amplitude with which the sinusoidal function of frequency u must be added to the others

sum infinite number of sinusoidal functions with continuously varying frequencies to obtain a generic function

Question 6

fourier analysis

Answer 6

all signals can be represented as a sum of sine waves

more frequencies present the better the signal is reproduced

Question 7

convolution

Answer 7

the overall effect is a substantial smoothing
(eg. low pass filters based on convolution with gaussian functions)

Question 8

acquisition with a single pixel

Answer 8

acquiring a digital image = sampling the convolutio between image and detector PSF with a sampling pitch equal to the acquisition step